[lic] Kemian tekniikan korkeakoulu / CHEM

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    Modelling of continuous casting of steel - recent developments and new prospects
    (2015) Oksman, Pilvi; Santasalo-Aarnio, Annukka; Kemian tekniikan korkeakoulu; Kemian tekniikan korkeakoulu; School of Chemical Engineering; Louhenkilpi, Seppo
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    Utilization of hydrometallurgical residues and minimization of energy consumption by regeneration of waste stream sulfates
    (2012) Scheidema, Madeleine; Metsärinta, Maija-Leena; Kemian tekniikan korkeakoulu; Kemian tekniikan korkeakoulu; School of Chemical Engineering; Taskinen, Pekka
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    Influence of fibrillar cellulose on pigment coating formulation rheology
    (2012) Dimic-Misic, Katarina; Hummel, Michael; Puunjalostustekniikan laitos; Kemian tekniikan korkeakoulu; School of Chemical Engineering; Paltakari, Jouni
    Coating suspension rheology influences the coating performance at high speeds. The quality of the coated and printed papers is also affected by the rheology of the suspension. For good coating results, it is crucial to optimize the water retaining properties of coating colours. The observation that fibrillar cellulose (MFC) could be used in paper coating formulations as a co-binder, since it is biodegradable and has good shear thinning properties, raises a question about the process ability of coating colours which have cobinder substituted with fibrillar cellulose. In this study, fibrillar cellulose is used to substitute the standard, synthetic co-binder material, carboxymethyl cellulose thus affecting both dewatering and rheological properties of coating colours. Reactivity of the MFC fibers in coating colour formulation is strongly dependent on the fineness of the fibrillar material as well as on its consistency, pre-treatment and refining route. In the present study the consolidation of coating colour layers has been studied using rheology as the main tool. This method combines the use of standard viscoelastic and static dewatering tools, Åbo Academy Gravimetric Dewatering Device and Brookfield viscometer, with the use of MRC300 Rheometer accompanied with an Immobilization cell. The rheological behaviour of all coating colours that have fibrillar cellulose as co-binders was found to be similar. Lower water retention and faster immobilization of filter cake were accompanied with higher shear thinning behaviour. This conclusion was strengthened by the recovery measurements, which showed that the fibrillar material containing coatings have a prolonged recovery time after high shear. A linear correlation between gravimetric (static) water retention and immobilization time, on the one hand and elasticity and prolonged recovery time on the other was found for fibrillar cellulose containing coating colours, regardless of the type of fibrillar material or pigment blend.
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    Biomimetic Oxygen Reduction at Liquid-Liquid Interfaces: From Electrocatalysis to Fuel Cell Applications
    (2012) Peljo, Pekka; Murtomäki, Lasse; Kemian laitos; Kemian tekniikan korkeakoulu; School of Chemical Engineering; Kontturi, Kyösti
    Research on new electro catalysts materials is important, because of the high price and restricted availability of the best available catalyst, platinum. In nature, oxygen reduction in cell respiration is catalysed by an iron porphyrin/copper center. Hence, similar biomimetic structures could be highly active and selective molecular catalysts. In this thesis oxygen reduction catalysed by a molecular catalyst is studied with electrochemistry at the interface between two immiscible electrolyte solutions (ITIES). Firstly, a hybrid fuel cell utilizing a liquid-liquid interface for H2O2 production is demonstrated. In this fuel cell hydrogen is oxidized at the anode as usual, but oxygen reduction catalysed by a cobalt porphyrin takes place at the water-1,2-dichlorobenzene interface by a redox mediator, which is regenerated at the cathode. Oxygen reduction is coupled with proton transfer from water to the organic phase to form hydrogen peroxide, which is extracted into an aqueous phase. Secondly, electrocatalysis of oxygen reduction by cofacial "Pacman" porphyrins is investigated at the lTIES. The experiments and density functional theory calculations show that oxygen reduction to H2O2 is catalysed when oxygen is bound on the exo side of the molecule, while four-electron reduction takes place with oxygen bound on the endo side of the molecule. A new mechanism is presented to explain the results.
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    Organic chlorine behaviour in activated sludge process
    (2011) Jokinen, Heini; Laukkanen, Timo; Puunjalostustekniikan laitos; Kemian tekniikan korkeakoulu; School of Chemical Engineering; Dahl, Olli
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    A thermodynamic assessment of the X-Pb (X = Co,Cr,Fe,Ni) binary systems
    (2011) Vaajamo, Iina; Luoma, Rauno; Materiaalitekniikan laitos; Kemian tekniikan korkeakoulu; School of Chemical Engineering; Taskinen, Pekka
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    Studies of synthesis, oxidation and surface assembly of cobalt and gold nanoparticles
    (2011) Doan, Nguyet; Johans, Christoffer; Kemian laitos; Kemian tekniikan korkeakoulu; School of Chemical Engineering; Kontturi, Kyösti
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    Interactions between bacteria and some papermaking components
    (2010) Leino, Taina; Stenius, Per; Puunjalostustekniikan laitos; Kemian tekniikan korkeakoulu; School of Chemical Engineering; Laine, Janne
    The aim of this thesis was a better understanding of the surface interactions between white water bacteria, Pseudoxanthomonas taiwanensis, and papermaking components, in order to make it possible to assess the importance of these interactions in papermaking processes. Flocculation of bacteria by cationic polyelectrolyte's in 0.01 M aqueous NaCl was investigated with electrophoretic mobility and turbidity measurements. The net charge of the bacteria was negative in a wide pH range. Cationic polyelectrolytes (poIyDADMAC, cationic polyacrylamide (C-PAM), cationic starch) adsorbed on the surface of the bacteria at pH 8. Polyelectrolytes functioning by bridging mechanism (C-PAM) were the most effective flocculants. Other polymers flocculated bacteria by charge neutralization. Thus, addition of typical retention polymers can flocculate bacteria and may attach them to the paper web. Adsorption of the bacteria and cationic polyelectrolytes on silica, cellulose, hemicellulose and extractive surfaces was investigated by quartz crystal microbalance with dissipation monitoring (QCM-D), atomic force microscope (AFM) and field emission scanning electron microscope (FESEM). Cationic polyacrylamide and poIyDADMAC increased bacterial adsorption on silica. The polyelectrolytes accumulated around the bacterial cells and prevented their aggregation on the surface at pH 8. The bacteria adsorbed on a cellulose surface as small aggregates in the presence of the polyelectrolyte. Hemicellulose (O-acetylgalactoglucomannan) promoted dramatically bacterial adsorption as large rafts on extractive surface at pH 4.7. Thus, bacterial adsorption on extractives may relate to pitch problems and biofilm formation in paper machine.
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    Kuparibentsoaattikompleksien sähkökemiallinen karakterisointi
    (2010) Repo, Eveliina; Murtomäki, Lasse; Kemian laitos; Kemian tekniikan korkeakoulu; School of Chemical Engineering; Kontturi, Kyösti
    In this work electrochemistry of immobilized and free Cu(II) benzoate compexes were studied. The literature part included an introduction of the grafting technique of electrode surface by reduction of diazonium salts, the properties of the grafted layers and the parameters that affect their properties, the properties of Cu(II) benzoate complexes in the solution and solid phase, and the effects of amine ligands on the properties of Cu(II) benzoates. In the experimental part the properties of the grafted electrodes as well as free Cu(II)-benzoate complexes were studied. At first, the blocking effect of benzoate groups immobilized on the gassy carbon and gold electrodes was investigated. The blocking was much more significant in the case of glassy carbon than gold. This was attributed to the lateral orientation of benzoate groups on the gold surface. In addition, the electrochemical properties of immobilized Cu(II) benzoate complexes were studied using cyclic voltammetry. Complexes formed on the god surface were unstable. The reaction mechanism of the Cu(II) benzoates grafted on the glassy carbon electrode was best described by the ECEC mechanism. Cu(II) centres were presented to locate in different environments on the layer and the large values of the peak widths observed in cyclic voltammograms were explained by the deviation of formal potential of Cu(II). Finally, the properties of free Cu(II) benzoate complexes with different amine ligands were studied. Amine ligands affected the stability of the complexes. The complex with pyridine ligands was found to be unstable. The characteristics of cyclic voltammograms of Cu(II) benzoate with bipyridine ligands indicated on the disproportionation reaction mechanism.
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    Phase behavior in chemical reactors
    (2010) Laavi, Helena; Biotekniikan ja kemian tekniikan laitos; Kemian tekniikan korkeakoulu; School of Chemical Engineering; Alopaeus, Ville
    In this work, chemical reactor modelling is discussed from a phase behaviour point of view. In trickle-bed reactors (TBR), the origin of many critical phenomena lies especially in dynamic phase changes and in the distribution of phases. For phase behaviour modelling purposes, two types of dynamic reactor models are presented: a trickle-bed reactor model and a gas phase particle model. In both models, special attention is focused on modelling the phase behaviour. In catalytic multiphase reactors, the same reaction can take place both in gas phase and in liquid phase. Therefore the effects that a phase can have on the reaction rate are discussed. Also a relation between a gas phase and a liquid phase adsorption coefficient is derived. Furthermore, the same kinetic model is used for isooctene hydrogenation in gas and in liquid phase. With respect to the modelling of phase equilibria, two types of non-ideal mixtures are presented. The applicability of SRK Boston-Mathias modification in calculating hydrogen solubility's in heavy hydrocarbons is tested. In addition, vapour-liquid equilibriua (VLE) are calculated for non ideal mixtures containing alcohol and hydrocarbon. Also numerical solving methods of a multiphase reactor model are discussed. The method of moments is presented and applied to the calculation of dynamic plug flow reactor state profiles.
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    Modern approaches to control of a multiple hearth furnace in kaolin production
    (Aalto-yliopisto, 2020) Gómez Fuentes, José Valentín; N/A; Kemian tekniikan ja metallurgian laitos; Department of Chemical and Metallurgical Engineering; Kemian tekniikan korkeakoulu; School of Chemical Engineering; Jämsä-Jounela, Sirkka-Liisa
    The aim of this thesis is to improve the overall efficiency of the multiple hearth furnace (MHF) in kaolin calcination by developing control strategies which incorporate machine learning based soft sensors to estimate mineralogy related constraints in the control strategy. The objective of the control strategy is to maximize the capacity of the furnace and minimize energy consumption while maintaining the product quality of the calcined kaolin. First, the description of the process of interest is given, highlighting the control strategy currently implemented at the calciner studied in this work. Next, the state of the art on control of calcination furnaces is presented and discussed. Then, the description of the mechanistic model of the MHF, which plays a key role in the testing environment, is provided and an analysis of the MHF dynamic behavior based on the industrial and simulated data is presented. The design of the mineralogy-driven control strategy for the multiple hearth furnace and its implementation in the simulation environment are also outlined. The analysis of the results is then presented. Furthermore, the extensive sampling campaign for testing the soft sensors and the control strategy logic of the industrial MHF is reported, and the results are analyzed and discussed. Finally, an introduction to Model Predictive Control (MPC) is presented, the design of the Linear MPC framework for the MHF in kaolin calcination is described and discussed, and future research is outlined.
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    Colloidal structures of phospholipids in vegetable oil and their potential usage in surface treatment of nanocellulose for food applications
    (Aalto-yliopisto, 2019) Lehtinen, Olli-Pekka; Bai, Long; Hokkanen, Sanna; Biotuotteiden ja biotekniikan laitos; Department of Bioproducts and Biosystems; Kemian tekniikan korkeakoulu; School of Chemical Engineering; Rojas, Orlando
    The aim of the licentiate’s thesis was to understand the colloidal behaviour of phospholipids in vegetable oils and to study the adsorption of phospholipid nanostructures onto the surface of cellulose nanofibrils. Water concentration, temperature and free fatty acid had an effect on the formation of reverse micelles of phospholipids in vegetable oil. At low water concentration, phospholipids formed solubilized reverse cylindrical micelles above critical micelle concentration (cmc) in the oil. Increasing temperature decreased the cmc of phospholipids in oil. Addition of moderate amount of water into oil caused solubilized phospholipids to form lamellar liquid crystal structures that were precipitated from the oil and formed separate phase. Oleic acid in rapeseed oil increased the solubility of lecithin and suppressed the formation of phospholipid reverse micelles at low water content. In presence of more water, the oleic acid stabilized the reverse micelles and consequently more water was needed to induce the phase separation. Thus it could be concluded that moderate amounts of oleic acid (5 wt.-%, 10 wt.-% and 20 wt.-%) in the oil delayed the removal of phospholipid reverse micelles upon addition of water, and the formation of lamellar structures required more water. This was caused by the increased solubility of lecithin into oil due to the co-solvent effect of oleic acid. Nanocellulose has shown many potential applications in foods, such as emulsifiers, fillers, structuring agents and cholesterol binders. An interesting application for nanocellulose would be the replacement of saturated fats in foods to decrease the fat content and the energy content of the products. To increase the compatibility of nanocellulose with the vegetable oil, the adsorption of phospholipid nanostructures was studied by immersing cellulose nanofibril film into the oily liquid containing phospholipid lamellar structures. The contact angle measurement seemed not to be an optimal way to measure the adsorption of phospholipids onto the surface of nanocellulose due to the variation in the results. Some of the contact angle measurement results indicated that the addition of the oily liquid containing phospholipid lamellar structures onto the surface of nanocellulose decreased the hydrophilicity of the surface after rinsing it with chloroform. In addition, two measurements indicated that the addition of oily liquid containing phospholipid lamellar structures decreased the hydrophilicity of the surface.
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    Viscose filterability and fiber wall pore size as a measure of pulp reactivity
    (Aalto-yliopisto, 2019) Lehtonen, Eeva; Borrega, Marc; Biotuotteiden ja biotekniikan laitos; Department of Bioproducts and Biosystems; Kemian tekniikan korkeakoulu; School of Chemical Engineering; Sixta, Herbert
    This study presents research on pulp properties and characteristics affecting the reactivity and accessibility of the pulps. Pulps with different production methods and wood species were selected for the tests. Mainly dissolving pulps were investigated, but in addition, one paper grade pulp was also included in the selection as a reference of hemicellulose-rich pulp. In order to comprehensively understand the cellulose structure, pulp samples were investigated at three different levels: molecular, supramolecular and morphological. The main method used in this study was the viscose filterability test (Treiber test), which determines the filterability value (FV) of viscose and describes pulp reactivity, which is understood as the processability and quality of the pulp. The Treiber test device was built and thoroughly evaluated for FV determination. Pulp accessibility (reactivity) was investigated by determining the pore size of the fibre wall. The methods included solid-state NMR (to determine the lateral fibril aggregate dimensions (LFAD)), the fibre saturation point (FSP) and BET measurements. The results showed that the production method of the dissolving pulp, as well as pulp’s chemical composition, macromolecular properties and other characteristics affect the pulp reactivity (FV). High hemicellulose content indicated poor reactivity (FV) and a lower CS2 -charge negatively affected reactivity. A relationship between the crystallinities measured by NMR and the viscose filterability was found. This result was not expected, due to the results of earlier studies. A correlation between the crystal width and the filterability value was also found. Viscose filterability increased parallel with increasing crystal width.
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    Africa Energy - A Tip of the Iceberg Overview
    (Aalto-yliopisto, 2017) Chandrasekhar, Sreenivasan; Hurme, Markku; Raiko, Risto; Kemian tekniikan ja metallurgian laitos; Department of Chemical and Metallurgical Engineering; Kemian tekniikan korkeakoulu; School of Chemical Engineering; Oinas, Pekka
    The status of energy supply and potential for exploitation of energy flows on the African continent in states between the ‘Maghreb’ in the north and borders of Republic of South Africa is charted out. To facilitate the analysis of the energy situation, the continent is divided into 6 sections and the energy sectors of each country are sub-divided as well: Hydroelectric power, Oil & Gas, Mining, Agriculture, and Renewable energy resources. The first part contains the land facts pertaining to a particular country’s energy situation. The analytical part of the work draws upon data in Land facts section plus some fresh references to trace out the energy belts of the continent and facilitate drawing of the energy maps. Calculations follow to estimate the densities of installed power and power potential vis-à-vis each country’s total area. A comparison of the power densities results in the scale-up factor, the bridge between present and future degrees of industrialization, whose magnitude is indicative of the land’s project engineering potential. The sheer magnitudes point to the scope for engineering activity – hydel in the central mass (where insolation stays diminished due to dense forest cover restricting water vapor’s evaporation and causing cloudiness), oil and gas offshore sites on the continent’s coastal sides, the grand coal patches, geothermal resources in the south and east and wind energy in the Horn of Africa and Sub-Sahara. Bioenergy potential from its myriad forms that straddle the continent from west to east and in pockets in the south.
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    Towards Cleaner Energy with Carbon-Based Catalysts: Density Functional Theory Studies of the Hydrogen Evolution Reaction
    (Aalto University, 2017) Pakkanen, Olli; Laasonen, Kari; Kemian tekniikan ja metallurgian laitos; Department of Chemical and Metallurgical Engineering; Kemian tekniikan korkeakoulu; School of Chemical Technology; Laasonen, Kari
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    Molecular dynamics simulations of heat transfer in gold nanoparticle-lipid bilayer systems
    (Aalto University, 2017) Potdar, Dipti; Sammalkorpi, Maria; Kemian tekniikan ja metallurgian laitos; Department of Chemical and Metallurgical Engineering; Kemian tekniikan korkeakoulu; School of Chemical Technology; Laasonen, Kari
    Nanoparticle-membrane interactions play a key role in many important applications such as drug delivery, nanomedicine, biosensors, electronic devices, imaging, diagnostics and cosmetics. Evidently, theoretical and experimental studies of nanoparticle and lipid bilayer interactions are major areas of research in the fields of soft matter and biophysical chemistry. However, complete understanding of these interactions with experimental methods can provide various scientific advances to bridge the gap between atomic level description of microscopic phenomenon and whole cell or system properties at various timescales. One such powerful technique in computational simulations is molecular dynamics (MD). In particular, here we adopt MD as a research tool for studying heat transfer characteristics of and results with reference to dipalmitoyl phosphatidylcholine (DPPC) lipid bilayer interacting with thiol functionalized 1) hydrophobic (hexane thiol ligand) and 2) hydrophilic (hydroxy pentane thiol ligand) gold nanoparticle heat source in presence of water. We demonstrate that, heat transfer MD simulations provide better qualitative understanding for the effect of nanoparticle position and type of ligand functionalization(s). Here, comparison of thermal conductivity and temperature distribution of both 1) hydrophobic nanoparticle (embedded inside membrane core) and 2) hydrophilic nanoparticle (placed in the proximity of bilayer heads and water) containing lipid bilayer system reveals that heat transfer in hydrophilic nanoparticle containing system is more efficient than in the system with hydrophobic nanoparticle. Additionally, heat transfer is asymmetric in such systems due to anisotropic nature of lipid bilayer. The findings discussed in this work may lead to a better understanding of heat transfer from heated gold nanoparticle source to lipid bilayer and of the light triggered release from GNP containing liposomes.
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    Factors affecting zinc dissolution from stainless steel production dusts using alkaline media
    (2015) Stefanova, Anna; Aromaa, Jari; Kemian tekniikan korkeakoulu; Kemian tekniikan korkeakoulu; Forsén, Olof
    Stainless steel production generates significant quantities of flue dusts that are considered as hazardous waste and are normally treated with pyrometallurgical methods in separate treatment plants. These dusts also contain valuable metals but the extraction and recovery of the valuables is difficult due their complex composition. Especially zinc content of the dust causes troubles in treating the dusts. In this thesis a hydrometallurgical method based on NaOH leaching was investigated as considered to be suitable for on-site treatment. The aim was to selectively remove zinc so that the remaining (Ni, Cr, Fe) oxide material could be recycled back to melting. The studied dust samples included argon-oxygen decarburization (AOD1 and AOD2) converter dusts and electric arc furnace (EAF1 and EAF2) dusts from the two production lines of Outokumpu Stainless Tornio Works. The effect of five different leaching factors (NaOH concentration, temperature, liquid-to-solid ratio, oxygen/nitrogen gas bubbling and agitation) on zinc dissolution was investigated using fractional factorial designs of the experiments. NaOH concentration, temperature and agitation affected zinc extraction predominantly and the greatest zinc extraction was achieved with high level of those three factors. The maximum amount of extracted zinc was: 80 % from AOD1, 50 % from AOD2, 60 % for EAF1 and 30 % for EAF2. Difference in zinc extraction between the dusts arose from the mineralogical differences. In all dusts zinc occurred both as easily soluble zinc oxide and as poorly- soluble ferrite form. This study showed that alkaline leaching of zinc from stainless steel AOD and EAF dusts using NaOH solutions is selective and practically no iron, chromium and nickel were dissolved. However, the dissolution of zinc is limited due to the presence of zinc ferrites. The leaching process can work in zinc removal if zinc ferrites are decomposed prior to leaching, for example by roasting.
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    Microwave-assisted total synthesis of tangutorine
    (2013) Kylmälä, Heli; Kemian tekniikan korkeakoulu; Kemian tekniikan korkeakoulu; Jokela, Reija
    Indole alkaloids are widely found from the nature. Many indole alkaloids show physiological activity and they can be used e.g. as anti-inflammatory agents and ß-adrenergic blockers. Since their isolation is not very profitable and the obtained isolated amounts are relatively small they have to be synthesized. There are many total syntheses reported for the pharmacologically important indole alkaloids. Microwave-assisted reactions are in the main focus in this licentiate thesis. Microwaves are abundantly used in organic syntheses. Microwaves speed up the reactions by transferring the energy directly to reacting molecules. Microwave assisted methods have enabled environmentally friendly reactions. Also solvent free reactions are possible. Reactions are also reproducible due to temperature and pressure control. Tangutorine is a biogenetically interesting indole alkaloid because to date it is the only known natural product containing the benz[f]indolo[2,3-a]quinolizidine unit. It was isolated from Nitraria tangutorum by Duan et al. in 1999. So far seven total syntheses as well as two formal syntheses and two synthetic approaches of tangutorine have been published. In this licentiate thesis the first microwave assisted total synthesis of tangutorine containing six steps where three of them were done with microwave irradiation is reported. In addition to microwave-assisted total synthesis of tangutorine, microwave-assisted monoacetal and -thioacetal protections of symmetrical dialdehydes are reported.
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    Production of recombinant proteins and monoclonal antibodies - Techno-enonomical evaluation of the production methods
    (Teknillinen korkeakoulu, 2009) Vermasvuori, Raisa; Kemian ja materiaalitieteiden tiedekunta; Hurme, Markku
    Terapeuttisia tai diagnostiikassa käytettäviä rekombinanttiproteiineja ja vasta-aineita voidaan tuottaa useissa eri tuotto-organismeissa (mikrobi-, hyönteis- tai eläinsoluissa), erilaisissa bioreaktoreissa (sekoitusreaktorissa, onttokuitureaktorissa tai kertakäyttöisissä pussireaktoreissa) sekä käyttäen erilaisia tuotantomenetelmiä (panos, puolipanos tai jatkuvatoiminen kasvatus). Tuotantokustannukset (euroa/g) riippuvat tuotto-organismin ominaisuuksista kuten kasvunopeudesta ja tuottavuudesta sekä tuottomenetelmästä kuten kasvatusvaiheen solutiheydestä sekä kokonaissaannosta. Kriittisimpiä tekijöitä ovat bioreaktorivaiheen tuotto sekä kokonaissaanto. Tässä työssä analysoitiin rekombinanttiproteiinin ja monoklonaalisen vasta-aineen pienen mittakaavan tuotannon taloudellisuutta. HIV-1 Nef-proteiinia tuotettiin erilaisissa tuottoorganismeissa (E. coli, P. pastoris and Drosophila S2) ja vasta-ainetta erilaisissa bioreaktoreissa. E. coli -bakteerin todettiin olevan edullisin tuotto-organismi HIV-1 Nef-proteiinin tuotannossa. Vastaaineen tuotannossa, onttokuitureaktorin tuotantokustannukset olivat hieman matalemmat kuin sekoitusreaktorin. Työssä esitellään myös kiteytysmenetelmä rekombinantti HIV-1 Nef-proteiinille.
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    Electrocatalysis of organic molecules on platinum catalysts surfaces: from the fundamentals to the polymer electrolyte fuel cell applications
    (Teknillinen korkeakoulu, 2009) Santasalo, Annukka; Kallio, Tanja; Kemian ja materiaalitieteiden tiedekunta; Kontturi, Kyösti
    Orgaanisia polttoaineita käyttäviä polymeerielektrolyyttipolttokennoja (PEPK) voidaan käyttää energianlähteinä pienissä, kannettavissa sovellutuksissa korkeiden tehotiheyksiensä vuoksi. Nestemäiset polttoaineet kuten alkoholit ovat kiinnostavia polttoaineita kuluttajasovellutuksiin, koska ne ovat turvallisempia ja helpompia käyttää kuin kaasumaiset polttoaineet. Vaikka orgaanisia polttoainevaihtoehtoja on tutkittu jo vuosikymmeniä, niiden adsorptiota ja hapettumista platinakatalyyttien pinnalla ei vielä tunneta kunnolla, mikä on edellytyksenä käytännön sovellusten suunnittelussa. Työn kirjallisessa osassa käsitellään orgaanisten molekyylien elektrokatalyysiä eli niiden adsorboitumista sekä hapettumista erilaisille platinakatalyyttipinnoille. Näihin ilmiöihin vaikuttavat erityisesti valittu elektrodimateriaali, liuoksissa olevat ionit ja molekyylit sekä elektrodin potentiaali, joiden matemaattisia tarkasteluja voidaan käyttää hyväksi arvioitaessa elektrodimateriaalin soveltuvuutta tietyn orgaanisen aineen elektrokatalyysiin. Kokeellinen osa koostuu kahdesta julkaistusta artikkelista sekä lisämittauksista yksikide-elektrodeilla. Ensimmäisessä artikkelissa on tutkittu erilaisten orgaanisten, pienimolekyylimassaisten komponenttien kulkeutumista paljon käytetyn Nafion 115 membraanin läpi ajan funktiona sekä näiden polttoaineiden suorituskykyä PEPK:ssa. Metanoli pienikokoisimpana, varautumattomana molekyylinä kulkeutui nopeitten tutkitun membraanin läpi, mutta sillä saatiin korkeimmat virrantiheydet platina-ruteniumkatalysoidussa polttokennossa. Vaikka muut molekyylit eivät saavuttaneet metanolin kaltaisia virrantiheyksiä, isopropanolilla saavutettiin metanolia huomattavasti korkeampi avoimen virtapiirin jännite. Toisessa julkaisussa on näiden tulosten pohjalta tutkittu metanolin, isopropanolin sekä niiden muodostaman seoksen hapettumista elektrodeilla, joiden pinta-atomit ovat järjestäytyneet yhden kiderakenteen mukaisesti. Korkeimmat virrantiheydet alkoholiseokselle kummassakin happamassa elektrolyytissä saatiin Pt(111) kidepinnalla, joten lisämittauksia suoritettiin elektrodeilla, joilla oli Pt(111) suuntautuneet terassit sekä Pt(100) tai Pt(110) suuntautuneet askelmat. Tämän lisäksi 2- propanolin sekä alkoholiseoksen hapettumistuotteita tutkittiin infrapunaspektroskopialla, jolla havaittiin että molemmat puhtaat alkoholit alkoholiseoksesta sekä adsorboituvat että hapettuvat Pt(111) pinnalla. Valitettavasti selvyyttä siihen miten alkoholiseos edesauttaa isopropanolin hapettumista, ei näillä mittausmenetelmillä saatu.